Technical Field
Certain embodiment of the present invention relates to a rotary drum-type magnetic separator which recovers a metal component from sludge included in a coolant liquid.
Description of Related Art
In polishing, cutting, or the like of a metal material, particularly, a magnetic material represented by a steel material, sludge-shaped cut chips, chips, or the like discharged along with a coolant liquid are separated from a liquid to be recovered. Since the cut chips, the chips, or the like have various shapes, various magnetic separation (recovery) devices are developed from the viewpoint of recovery efficiency.
For example, since the chips are powdery, the chips are easily collected and are likely to contain a liquid. Accordingly, a magnetic separation device which favorably separates the liquid of the sludge is required. For example, FIG. 1 is a sectional view taken along a surface orthogonal to a rotary shaft of a rotary drum showing a configuration of a rotary drum-type magnetic separator of the related art.
As shown in FIG. 1, in the rotary drum-type magnetic separator of the related art, a liquid reservoir portion 2 which stores a coolant liquid is provided inside a box-shaped main body 1. In addition, a rotary drum 3 is pivotally supported in an approximately horizontal direction in the vicinity of a center portion of the main body 1 so as to divide the liquid reservoir portion 2 into two. The rotary drum 3 is a cylindrical body formed of a nonmagnetic material such as stainless steel, and inner tube 5 in which a plurality of magnets 4, 4, . . . are disposed in a predetermined arrangement on the outer peripheral surface is coaxially fixed to the inner portion of an outer tube 9. In the plurality of magnets 4, 4, . . . , in order to magnetically attach cut chips, chips, or the like included in the coolant liquid, magnetic poles are disposed to generate a predetermined magnetic flux on the outer peripheral surface of the rotary drum 3.
In the example of FIG. 1, the plurality of magnets 4, 4, . . . are disposed from a portion in which the rotary drum 3 is immersed into the liquid reservoir portion 2 to a top portion, that is, on the inner tube 5 corresponding to a portion equivalent to approximately ¾ of the outer periphery of the rotary drum 3. In a portion corresponding to the approximately remaining ¼, the magnets 4, 4, . . . are not disposed on the inner tube 5 and a magnetic force does not act on the portion.
The cut chips, the chips, or the like, which are magnetically attached to the outer peripheral surface of the outer tube 9 on the bottom portion of liquid reservoir portion 2 by the magnetic forces of the magnets 4, 4, . . . , are transported to the top portion of the rotary drum 3 according to the rotation of the outer tube 9, magnetization forces generated by the magnetic forces of the magnets 4, 4, . . . are released at the time point at which the cut chips, the chips, or the like pass through the top portion, and the cut chips, the chips, or the like are scrapped off by a scraper 7 abutting on the rotary drum 3 so as to be recovered. A squeezing roller 6 in which an elastic body such as rubber is disposed on the surface is provided in the vicinity of the top portion of the rotary drum 3 and abuts on the outer peripheral surface of the outer tube 9 of the rotary drum 3 by predetermined pressing. The magnetically attached sludge passes through a portion between the outer tube 9 and the squeezing roller 6, a liquid of the sludge is squeezed out, and the cut chips, the chips, or the like are separated and recovered at the time point at which the sludge passes through the top portion of the rotary drum 3, that is, a position at which the magnetic force of the magnet 4 is not applied.
In the above-described rotary drum-type magnetic separator of the related art, it is possible to purify the coolant liquid up to a certain level. However, recently, it is required to perform purification to be the coolant liquid having high cleanness. Meanwhile, for example, in the related art, a plurality of magnetic separation devices are disposed in multiple stages so as to provide a coolant liquid having higher cleanness.
Moreover, in the related art, a purifying device is disclosed, which includes a first rotary drum in which a plurality of magnets are disposed on the outer peripheral surface, and a second rotary drum which is disposed so as to be close to the first rotary drum and in which a plurality of magnets are disposed on an outer peripheral surface to which suspended solid matters adsorbed to the first rotary drum and transported therefrom are delivered.